A high-resolution and harmonized model approach for reconstructing and analysing historic land changes in Europe

Human-induced land use changes are nowadays the second largest contributor to atmospheric carbon dioxide after fossil fuel combustion. Existing historic land change reconstructions on the European scale do not sufficiently meet the requirements of greenhouse gas (GHG) and cli- mate assessments, due to insufficient spatial and thematic detail and the consideration of various land change types. This paper investigates if the combination of different data sources, more detailed modelling techniques, and the inte- gration of land conversion types allow us to create accu- rate, high-resolution historic land change data for Europe suited for the needs of GHG and climate assessments. We validated our reconstruction with historic aerial photographs from 1950 and 1990 for 73 sample sites across Europe and compared it with other land reconstructions like Klein Gold- ewijk et al. (2010, 2011), Ramankutty and Foley (1999), Pon- gratz et al. (2008) and Hurtt et al. (2006). The results indicate that almost 700 000km2 (15.5%) of land cover in Europe has changed over the period 1950–2010, an area similar to France. In Southern Europe the relative amount was almost 3.5% higher than average (19 %). ... mehrBased on the results the specific types of conversion, hot-spots of change and their relation to political decisions and socio-economic transitions were studied. The analysis indicates that the main drivers of land change over the studied period were urbanization, the reforestation program resulting from the timber shortage af- ter the Second World War, the fall of the Iron Curtain, the Common Agricultural Policy and accompanying afforesta- tion actions of the EU. Compared to existing land cover re- constructions, the new method considers the harmonization of different datasets by achieving a high spatial resolution and regional detail with a full coverage of different land cat- egories. These characteristics allow the data to be used to support and improve ongoing GHG inventories and climate research.